A modular battery system for a material handling vehicle is provided. The modular battery system includes a counterweight assembly, a battery assembly enclosing a power source and including a battery base, and a pair of channels removably coupled to the battery base and laterally separated from one another to define a counterweight slot therebetween. The battery assembly is configured to be slidably installed onto the counterweight assembly with the counterweight assembly received within the counterweight slot defined between the pair of channels.